Regulator



AU Z52 April 15, 1941.

F. H. GULLlKSEb l Original Filed Nov. V21', 1937 )CKUSS Ll-mum:

2 Shoots-Sheet 1 INVENTOR fill/7 I). 6ul/iksen.

ATTORNEY qwfa O '2 O 1 UKUSS KtrtKtNUt EXAMINE April 1941- F. H. GULLIKSEN 2,238,639

mam-non Original Filed Nov. 27, 1937 2 Sheets-Sheet 2 wrmssszs: INVENTOR Patented Apr. 15, 1941 REGULAT OB Finn H. Gullikpen, Pittsburgh, Pa... asuignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation Pennsylvania Original application November 27, 1937, Serial No.

Divided and this application August 18, 1939, Serial No. 290,739

(Cl. 1'l1312) 8 Claims.

My invention relates to electronic regulators and particularly, to indicating means adapted to initiate the control of regulators for governing a regulated quantity, such as the voltage of a generator, of a speed of a motor in response to a regulated quantity from its desired value.

This application is a division of my copending application Serial No. 176,864, filed November 27, 1937, for Regulators." patented June 18, 1940, No. 2,205,254, and assigned to the same assignee as this application.

In practicing my invention, I make use of a centrifugal device that is actuated in accordance with the value of the regulated quantity and which controls a phototube in accordance with variations in the regulated quantity as determined in variations in the speed of the centrifugal device from a critical value.

One object of my invention is the provision of an electronic regulator that is reliable and accurate in operation and that is quick and positive in response to changes in the regulated quantity from the desired value.

Another object of my invention is the provision of an electronic regulator or indicator that possesses a high degree of sensitivity at the chosen value of the regulated quantity.

Further objects and advantages of my invention will be apparent from the-following description of one preferred embodiment thereof, reference being had to the accompanying drawings, in which:

Figure 1 is a schematic diagram of circuits and apparatus constituting one preferred embodiment of the invention;

3 Figs. 2 and 3 are plan and side elevational d views, respectively, of a portion of th speed responsive device employed in the regulator system in Fig. 1;

Fig. 4 is a diagrammatic view illustrating'the 40 principle of control of the phototube employed in the regulator system in Fig. 1;

Flg. 5 is a plan view of a modified control to be employed in the speed responsive device; and

Fig. 6 is an elevational view of the control tube shown in Fig. 5, together with a schematic illustration of the phototube controlling circuit connections.

Referring to Figure 1 of the drawings, a regusource of direct-current energy, such as the con- 55 'lated motor I is illustrated provided with an ductors i and 1. The generator l is illustrated as being provided with a field winding 8 that is supplied with energy from the conductors 6 and 1 and a field winding 9 that is connected to the armature I! 'of an exciter generator 13, that is provided with a field winding H, the energization of which determines the output of the exciter generator l3 and consequently, oi the main generator 4 to control the energy supplied to the motor I.

A speed responsive device indicated generally at is is provided that is connected through a speed-changing mechanism ii to vary th ratio between the motor-driven shaft l1 and a shaft l8 driving the speed responsive device, in order to adjust the speed responsive device to so control the motor I as to maintain adesired rate of speed. The speed responsive device I5 comprises a source of illumination it, from which a. beam of light is focused by a lens 12 through a glass tube section 21, an aperture in a diaphragm 23 upon a phototube 24 as controlled by fluid in the U-shaped tube 25 of the speed responsive mechanism. The tube 25 consists in its elementary form of two vertical tube sections 2 and 21 respectively, connected by an intermediate section 28, and so mounted as to be revolved substantially about the axis of one of the vertical tube sections 21, so that centrifugal force acting upon the liquid within the tube 25 will cause an increasing volume of the liquid to flow toward the outer leg 26 of the U-shaped tube as the speed of the device increases, thus lowering the level of the liquid in the tube section 21. The illumination of the phototube it from the source I! is controlled by the level of the liquid in the central leg 21 of the U-shaped tube.

The phototube 24 controls the grid potential of a control tube II which in turn controls the grid potential of rectifying tubes 32, 33 and 34, in a manner to be later described, for controlling the energy supplied to the field winding H of the exciter generator l3.

A suitable alternating-current source, repre-Q sented by conductors I5, 36 and 31, is provided for supplying three-phase energy to a transformer winding 39 shown connected in delta and inductively coupled to transformer secondary windings 39 and 42. The windings 39 constitute an anode transformer having the several phase winding portions connected in double Y relationship, theouter terminals be ng connected to the anodes ll of the respective rectifying tubes 32, 33 and II, and the neutral point 44 being nected by. conductor 45 through a rheostat 4Q to one terminal of the exciter field winding ll. The other side of the field winding I4 is connected by conductor 41 to the cathodes ll of the rectifier tubes through the secondary winding ll of a grid transformer having a primary 5 age at the terminals II and II that is applied across aresistor I! for apurposetobelater ex-.

plained.

The grid circuit of the rectifier tubes 32, 33 and 84 extends from the cathodes ll, through transformer winding 4!. conductor '1 to junction point II, the left portion of resistor I! to the positive terminal ll of the rectifier it through resistor I8 and conductor II to Junction point I! of the ripple transformer 42, through the several individual branch circuits of the three-phase transformer winding to the three grids ll associated with the severalmbes 32, I8 and N. The

ll connects the left-hand terminal of resistor section 02, thus connecting the resistor sections I I2 and 03 between junction point II and conductor 10.

The details of construction of the speed responsive device will be better understood by reference to-Figs. 2 and 3, in which the revolving tube 25 is illustrated as provided with an outer enlarged cup portion III connected through an 10 intermediate section 20 having a portion I" that is arranged substantially circumferentially with respect to the axis of rotation, and a portion In that extends substantially radially from the axis of rotation, and provided at its inner end with an enlarged volume Ill Just below the upwardly extending section 21. A liquid of high specific gravity. such as mercury, indicated at III, is provided in the lower connected portions of the tube. above which a liquid of lower specific 2o gravity, such as-alcohol or water, indicated at Ill. is provided in the inner or axially located leg of the device.

Neglecting the weight of the liquid 1, the

heavy liquid I" will seek its level in the two g5 tubes and 21 when the device is at rest, and

will rise in the outer tube 28 due to centrifugal force as the speed of revolution about the axis of the leg 2| increases. The provision of a cup or an enlarged portion ll! of larger diameter control tube ll governs the potentials 0! the so than the inner tube permits a relatively large grids 08 by controlling the fiow of current from the positive terminal of the resistor ll through resistor II to the negative terminal of the resistor l1, thus varying the voltage drop across resistor ll cathode heater I! that is connected to a seconds. ary'winding 18 inductively related to the grid transformer primary winding II.

The grid control circuit of the control tube 8| extends from the cathode OI through conductor II, a quick response network ll, conductor ll.

- an anti-hunting network ll, conductor is and grid resistor II to the control grid ll. The control grid is is also connected through a resistor I and capacitor 82 to the cathode II to bypass alternating-current ripples.

The anti-hunting network ll includes a resistor IS, the terminals of which are connected by conductors Ii and II, respectively. to the terminals of the exciter armature winding II. A condenser l! is connected to an intermediate point of the resistor 08 in parallel circuit relation to a resistor 80 and the lower portion 8'! of the resistor 88, to modify thegrid potential in a manner to be later explained.

The quick response network ll includes a condenser ll connected in aerieswith a resistor section I! in parallel circuit relation with a resistor II. A resistor section it is also provided that is connected between the junction of sections l2 and II and conductor II. The resistor sections I! and It in series comprise a resistor to which a unidirectional voltage is applied from a source indicated by conductors N and II as controlled by the phototube 24. A resistor is is provided between the positive conductor 04 and conductor II, and a resistor I! is provided between the source terminal conductors I and I8,

quantity fiow of the heavy liquid from thetube II to the tube 28 with a comparatively slight increase in the level of the liquid in the cup ll! as indicated by the lines I II and I. This permits a greater change in the level of the liquid in the tube 21 for a given change in speed before the centrifugal force is.balanced by the force of gravity than would take place if the liquid rose in the outer leg I! an amount correspond- .40 in to its drop in the inner leg 21, thus increasing the sensitivity of the device. The provision of the enlarged area I" at the Junction of the vertical tube portion fl with the horizontal tube portion I further increases the sensitivity .of

5 the device by maintaining the radial portion of the tube ill substantially filled with the heavier liquid. That is to say, as the liquid ill moves downwardly through the tube 21 until a small portion of it enters the enlarged chamber Ill,

this lighter weight liquid will extend only a very small distance circumferentially from the axis of rotation outwardly within the tube m, o'ecause a relatively large movement of the level of the liquid in the tube 21 is required to introduce an appreciable volume in the chamber Ill.

Consequently, the liquid acted upon by the centrifugal force of rotation in the chamber I and in tube section I is at all times substantially the heavier liquid I alone. so Fig. 4 illustrates the refractory action of the liquid I" in the upper portion of the tube 21, through which the light beam is focused by the lens 22. For the purpose of simplifying and understanding this phenomena, the tube 21 is as shown somewhat enlarged. The light beam from the source ll is focused by the lens 22 to hit the glass tube I! at one side of its center, and the beam will be refracted along the line II! when the liquid "1 is in the portion of the tube 21 7o traversed by the light beam, thus making the tube 24 more conductive. when the level of the liquid ll'l drops in the tube 2'! below the level at which the light beam intersects the tube, so that the central portion of the tube contains air to an intermediate point ll of which a conductor instead of water or alcohol, the light beam will be refracted in the direction indicated by the dottedlinellisothatthislightbeamwillnot sensitize the phototube 24, which will be less conductive.

The operation of the system is as follows. When the motor I is operating at its desired speed, the centrifugal force acting on the liquid in the tube 2' of the speed responsive device it is such that the surface level of the liquid I" is substantially in the plane of the light beam from the source I. to the tube 24. As the motor speed decreases slightly below its desired speed, the centrifugal force will correspondingly de-' crease and permit the force of gravity acting on the liquid to raise .the level of the liquid Ill slightly, swinging the light beam to position 2 in Fig. 4 and making the tube 24 more conducting, while as the speed increases slightly above the desired speed, the liquid ill will lower slightly below the plane of the light beam by the increasing centrifugal force, changing the beam to the position H3 in Fig. 4 to make the phototube 24 less conducting.

When, for example, the motor speed decreases slightly below its desired value, causing the conductivity of the phototube 24 to increase, the flow of current from the positive conductor 24 through resistor Oi, conductor H4, the positive terminal H5 and negative terminal ll. of tube 24 and to conductor 25, will increase the voltage drop across resistor it and consequently, decrease the voltage across the resistor 83 in the grid circuit of the control tube Ii, making the potential of the grid 68 more negative.

As the control grid 88 becomes more negative, the current through the tube 31 between the anode 64 to the cathode 49 decreases, thus decreasing the flow of current from the positive terminal 55 of the full-wave rectifier, through resistor 58 and tube ii, to the negative terminal 55, which decreases the voltage drop across the resistor 58. This decrease in voltage drop across resistor 58 causes the grids B2 of the rectifier tubes 32, 33 and 34 to become more positive, thus increasing the flow of current through the rectifler tubes to correspondingly increase the excitation of the exciter generator I3 and of the maingenerator 4, to increase the speed of the motor I.

when the voltage between conductors l6 and 9a is changed in either direction, a current flows to or from the condenser II as a result of the changing potential across its terminals in the local circuit of resistors 82 and .2, the values of these resistances being so proportioned with respect to each other and to the resistor 23, that the voltage between conductors l4 and the lunction point of the three resistors '2, Cl and I! will be greater than the voltage change between conductors l4 and I8, so that the voltage variation in the grid circuit is greater than the voltage variation between conductors II and it. Therefore, when a voltage between conductors l8 and 28 changes in either direction as above described, the potential change on the grid 4| is caused to be greater than it would otherwise be by the action of the quick response network.

An anti-hunting influence is brought into the cause; her ism-er:

the regulator action. For example, when the grid 48 has been made more negative by the regulator action to increase the excitation of the exciter field winding i4, this increase in potential causes ch r in current to flow downwardly through resistor I. so that the upper end of the resistor ll is more positive than the lower end to increase the potential of the grid 68 to provide the necessary anti-hunting action.

It will be seen, therefore, that a decrease in the motor speed below the critical value renders the phototube 24 more conductive, making conductor I. and the grid 68 of the control tube 3| more negative to cause a smaller value of current to flow through the tube ii. The reduced voltage drop across the resistor 58 causes the grids 63 to become less negative to permit a greater value of current to flow through the tubes 32, I3 and 24 to increase the energization of the exciter field winding l4 and cause the motor speed to increase. Similarly, as the motor speed drops below its critical or desired value, the phototube 24 is made less conductive, thus increasing the potential on the grid 88 and causing the control tube 3| to pass more current and the rectifiertubes 32, 33 and 34 to pass less current to decrease the excitation of the exciter generator field winding l4 to correspondingly decrease the speed of the motor I.

If desired, the speed responsive element of the regulator may correspond to that shown in Figs. 5 and 6, in which the two vertical tube sections 25 and 21 contain a single liquid, the level of which interrupts the beam of light from the source It to the tube 24 when above the level of the light beam and permits light to flow when the level of the fluid is below the level 'of the light beam. In this case, the connection of the terminals of the tube 24 will be reversed from that shown in Fig. l, and the potential of the light source conductors 95 and 94 will also be reversed in order to produce the correct direction of voltage change between conductors l6 and 89, as the liquid in the tube rises above and below the level of the light beam.

regulator action by the network II, which upon -causes a current to flow to or from the condenser through the resistor II to introduce into the grid control circuit a voltage component It will be noted that the portion of the tube I03 containing an appreciable volume of fluid such as mercury, is in a direction extending substantially circumferentially of the axis of rotation, so that a change in the rate of speed of rotation of the tube about its axis causes flow of liquid, thus making the device responsive to changes in acceleration as well as to changes in speed. If, for example, the speed responsive devices are revolved in a counter-clockwise direction, as shown in Figs. 5 and 2, an increase in the rate of speed will cause more fluid to flow into the tube 2' from the tube 21 due to the inertia of acceleration than would flow from centrifugal force alone. This causes the level of the liquid in the tube 21 to fall below the level of the light beam from the source is to the phototube 24 before the completion of a speed correction, to thus introduce a stabilizing or antihunting action into the regulator. A'deceleration in motor speed similarly creates a force of inertia causing fluid to flow from the tube 26 to the tube 21 to raise the tube level, this force being separate from the centrifugal force acting radially from the axis of rotation of the device. This inertia component of force causes the liquid in the vertical tube portion 21 to drop below the level of the light beam sooner than it would from centrifugal action alone, thus providing an anti-hunting influence. It will be apthat opposes the change in grid voltage causing preciated, therefore, that the design of the speed speed of said motor from a responsive device is such that the liquid level is variedbothinresponsetoachangeinmotor speed, and also in response to motor acceleration "l'l is unnecessary and may be omitted.

Many modifications in the apparatus and circuits illustrated and described may be made within the spirit of my invention, and I do not wish to be limited otherwise than by the scope of the appended claims.

I claim as my invention:

i. In a speed regulating equipment, an electric motor to be regulated, and means for controlling the speed of said motor including a field winding circuit, a grid-controlled tube for controlling the current in said field winding circuit. and means for controlling the grid potential of said tube including a speed indicating device comprising a phototube, a source of illumination therefor and inertia means actuated in accordance with the speed of said motor for controlling said phototube, said inertia means comprising a liquid container mounted to revolve about an axis, a liquid in said container subject to the centrifugal force of revolution of said container.

2. In a regulator system, an alternating current circuit, a direct-current motor, means for controlling the speed of said motor comprising an exciter generator having a field winding and grid-controlled rectifier means for supplying a unidirectional current to said field winding, means for controlling the current output of said rectifier means in response to variations in the speed of said motor from a desired value comprising a grid control circuit and means for varying the grid potential including a speed indicating device comprising a phototube, a source of illumination therefor and inertia-means actuated in accordance with the speed of said motor for controlling said phototube, said inertia means comprising a liquid container mounted to revolve about an axis, a liquid in said container subject to the centrifugal force of revolution of said container.

3. In a speed regulating equipment, an electric motor to be regulated, and means for controlling the speed of said motor including a field winding circuit, a grid-controlled tube forcontrolling the current in said field winding circuit, and means for controlling the grid potential of said tube including a speed indicating device comprising a phototube, a source of illumination therefor and inertia means actuated in accordance with the speed of said motor for controlling said pho-,

totube, said inertia means comprising a liquid container having a portion extending substantially axially thereof and a portion extending substantially radially thereof for varying the level of the liquid in the axial portion by the centrifugal force of revolution of the inertia means.

4. In a regulator system, an alternating-current circuit, a direct-current motor, means for controlling the speed of said motor comprising an exciter generator having a field winding and grid-controlled rectifier means unidirectional current means for controlling the current output of said rectifier means in response to variations in the desired value comprising agrid control circuit and means for varying the grid potential including a speed indieating device com rising a phototube, a source of illumination therefor and inertia means actuatedinaccordancewiththespeedofsaidmotor for controlling said phototube, said inertia means comprising a liquid container having a portion extending substantially axially thereof and a portion extending substantially radially thereof for varying the level of the liquid in the axial portion by the centrifugal force of revolution of the inertia means.

5. In a speed regulating equipment, an electric motor to be regulated, and means for controlling the speed of said motor including a field winding, a grid controlled tube for controlling the current in said field winding circuit, and means for controlling the grid potential of said tube including aspeedindicatingdevicecomprisingatubmar container having two vertical leg portions and a connecting portion containing a liquid-mounted to revolve about an axis that is substantially coincident with one of said vertical leg portions, the portion of said tube connecting said two vertical portions extending radially and circumferentially with respect to the axis of rotation, the area of said container adiacent the juncture of said axially located leg and said connecting portion having an enlarged cross-section, a phototube and-a source of illumination therefor arranged to illuminate said phototube as controlled by the level of the liquid in said axially located leg portion,md circuit means responsive to the control of said phototube.

6. In a need regulating equipment, an electric motor to be regulated, and means for controlling the speed of said motor including a field winding, a grid controlled tube for controlling the current in said field winding circuit, and means for controlling the grid potential of said tube including a speed indicating device comprising a tubular container having two vertical leg portions and a connecting portion containing a liquid mounted to revolve about an axis that is substantially coincident with one of said vertical leg portions, the other of said leg portions being of greater diameter than the axially located leg portion, the

portion of said tube connecting said two vertical portions extending radially and circumferentially with respect to the axis of rotation, a liquid of relatively high specific gravity in the body of said container and a liquid of relatively light specific gravity in the axially-disposed leg thereof above the first-named liquid, a phototube and a source of illumination therefor arranged to illuminate said phototube as controlled by the level of the liquid having relatively light specific gravity, and circuit means responsive to the control of said phototube.

7. In a speed regulating equipment, an electric motor to be regulated, and means for controlling the speed of said motor including a field winding, a grid controlled tube for controlling the cu rent in said field winding circuit, and means for controlling the grid potential of said tube including a speed indicating device comprising a tubular container having two vertical leg portions and a connecting portion containing a liquid mounted to revolve about an axis that is substantially coincident with one of 'said vertical leg portions. the portion of said tube'connectin said two vertical portions extending radially and circumferentially'with respect to the axis of rotation, the

area of said container adjacent the juncture of said axially located leg and said connecting portion having an enlarged cross-section, a liquid of relatively high specific gravity in the body of said circuit means responsive to the control of said phototube.

8. In a speed regulating equipment, an electric motor to be regulated. and means for controlling the speed of said motor including a field winding, a grid controlled tube for controlling the current in said field winding circuit, and means for con-- trolling the grid potential of said tube including a speed indicating device comprising a tubular container havin two vertical leg portions and a connecting porti 11 containing a liquid mounted I to revolve about an axis that is substantially coincident with one of said vertical leg portions, the

other of said leg portions being '01 greater diameter than the axially located leg portion, the portion of said tube connecting said two vertical portions extending radially and circumferentially with respect to the axis of rotation, the area of said container adjacent the juncture of said axially located leg and said connecting portion having an enlarged cross-section, a liquid oi relatively high specific gravity in the body oi said container and a liquid of relatively light specific gravity in the axially disposed leg thereof above the first-named liquid, a.phototube and a source of illumination therefor arranged to illuminate said phototube as controlled by the level oi the phototube.

liquid having relatively light specific gravity, and circuit means responsive to the control of said FINN H. GUILIKSEN. 

